Increasingly, for agricultural machines electronic control of one or more functional elements of the agricultural machine is used.
A common standard, namely ISO 11783, was proposed for providing a network infrastructure for transmitting data signals between the various devices that may compose an agricultural machine. In addition to the transmission of control or data signals, the network infrastructure may be used for providing power supply to the various devices connected to the network infrastructure, e.g. from a tractor power supply to functional or working elements of an implemented connected to the tractor. While the control or data signals are transmitted over signal or data lines of the network structure which may also be referred to as communication lines, power supply may be applied over one or more power supply lines provided by the network infrastructure, such power supply line being established separately from the data lines used for a data or signal transmission.
With respect to the network infrastructure, a common data or control bus is provided to which different components of the agricultural system are connected. Through the data or signal bus data can be exchanged between the components connected to the bus. Among the components there may be a user terminal, and a plurality of electronic control units (ECU) each of which is assigned to a functional or working element of the agricultural machine or system, e.g. an implement connected to a tractor. The electronic control unit provides control signals to the functional element assigned to the respective electronic control unit for operating the functional or working element. Such functional element may refer to an element of a tractor or a functional element of an implement. In conclusion, the network infrastructure may provide for data communication within a tractor or between the tractor and an implement connected to the tractor.
According to a method of operation, user input is received through the user terminal. From the user input control signals are generated and transmitted to the electronic control units for controlling operation of the functional elements of the agricultural machine. It has been proposed to use auxiliary devices for controlling operation of the agricultural machine (see, EP 2 821 864 A1), e.g. a joystick or some other hardware element providing the option of receiving user input. Such auxiliary devices are used for controlling auxiliary functions of one or more functional elements of the agricultural machine. Through the user terminal input function of the auxiliary device can be mapped to control functions of the functional element of the agricultural device. For example, by moving a joystick functionally connected to the user terminal via the data bus, through the user terminal control signals are provided to the electronic control unit for which the control function is mapped to the joystick operation. Operation of the functional element assigned to the electronic control unit is controlled through a chain of operation from the joystick to the user terminal and finally to the functional element via the electronic control unit.
Document U.S. Pat. No. 5,918,195 discloses a method of generating a calibrated command signal in a control system including a command device. The command device, e.g., a control lever, is movable between pre-defined positions.
Document EP 1 997 686 A2 discloses a device for transmitting electrical energy from a tractor to an implement connected to the tractor. AC voltage is generated by a generator. Following, the AC voltage is transformed by a converter, thereby, providing a DC current. The DC current is provided to an intermediate DC voltage circuit of the tractor. There is a DC voltage of about 700 Volt. Converters are connected to the intermediate DC voltage circuit for transforming the DC current into AC current. An AC voltage in the range of about 400 V to 480 V is provided. The AC current is provided to a transformer transforming the AC voltage into an AC voltage from 200 V to 240 V. The converters connected to the intermediate DC voltage circuit are configured to provide different AC currents, for example, several AC currents having different frequencies. The different AC currents are applied to drive different functional elements of the implement.